Currently in networks using the 3GPP (3rd Generation Partnership Project) standard, roaming footprint control is typically a two step process. Roaming is the condition when a user takes her mobile station outside her Home Public Mobile Network (HPMN) and attempts to use it. The HPMN is the network serviced by the network provider in which the user has her subscription. A Visited Public Mobile Network (VPMN) is the network into which the user has entered. The networks may be a wireless mobile communication network and may be implemented as a network conforming to the IMS standard, and/or as a network conforming to the code division multiple access (CDMA) IS-95 standard, the 3rd Generation Partnership Project 2 (3GPP2) wireless IP network standard or the Evolution Data Optimized (EVDO) standard, the 3GPP LTE standard, the 4G LTE, the Global System for Mobile (GSM) communication standard, a time division multiple access (TDMA) standard or other standards used for public mobile wireless communications.
LTE is one of the best mobile broadband data technologies available and has been adopted by global carriers as their future technology direction. However, there is no harmonization of LTE spectrum. There are more than 30 different radio frequency (RF) bands that can be used for the LTE service, as well as differences in implementation in terms of carrier bandwidths (1.4 MHz to 20 MHz), paired or unpaired spectrum (FDD/TDD), and in the future, various permutations with LTE carrier aggregation. Packing all the potential power of LTE in a compact global phone form factor is a formidable challenge. Hence a need exists for a system that enables high quality mobile voice and multimedia services over the LTE network across the world, regardless of the operating frequency band of the LTE network and without a need for a large form-factor handset on an every-day basis.